1. Technology Field
The present invention relates to a data writing method for a flash memory, and more particularly, to a data writing method for a flash memory with a data protection mechanism, a flash memory controller and a flash memory storage drive using the data writing method.
2. Description of Related Art
With the booming market of digital cameras, camera cell phones and MP3s in recent years, demand for memory storage devices by consumers are rapidly increasing. Flash memories having the advantages of non-volatility, power-saving, small size and having no mechanical structure are suitable in portable applications, especially suitable for these types of portable products that are powered by batteries. In addition to the demand of memories embedded in products, there may also be an even larger market of mini memory cards and USB flash disks because a single user may own multiple USB flash disks and mini memory cards. Therefore, the flash memory industry has become extremely demanding in the electronics industry in recent years.
Flash memories have been developed from a single level cell NAND flash memory to a multi level cell NAND flash memory. Due to physical characteristics of the multi level cell NAND flash memory, electronic charges may be unstable in programming some pages of the flash memory, which may affect adjacent pages. Therefore, the multi level cell flash memory has a poor storing reliability despite of its large storage. On the other hand, the storage of the multi level cell flash memory is becoming larger and larger, which makes it increasingly suitable for being used as hard disks (e.g., solid state drives). Under this situation, whether the solid state drive employing the flash memory as storage medium is able to prevail in the market depends mainly on the data storage reliability.
What is needed, therefore, is a data writing method that can increase the reliability in storing data to the flash memory.